beaedsley



UNITED STATES PATENT OFFICE.

TRUMAN J. PEARCE AND MELVIN NV. BEARDSLEY, OF OAKLAND, A

TO THE PARAFFINE PAINT COMPANY, OF SAN FRANCISCO, (AL

INSULATING WIRE AND CONDUCTORS FOR ELECTRICAL PURPOSES.

SPECIFICATION forming part of Letters Patent No. 348,994, datedSeptember 14, 1886.

Application filed March 21, 1895.

March 30, 1886, No. 162.442, and in 'Ilclgium March 30, 1981;.

To all whom, it play concern.-

Be it known that we, TRUMAN J. PEARCE and llIEIXI-N XV. BEARDSLEY,citizens of the United States, residing in the city of Oakland,

5 Alameda county. State of California, have invented certain new anduseful Improvements in Insulating \Vire and Conductors for ElectricPurposes; and we do hereby declare. that the following is a full, clear,and exact description of our said invention and of the manner in whichwe produce, apply, and carry out the same.

Our invention relates to improvements made in coating or covering wiresand conductors 1 for electrical purposes with an insulating water-proofand weatherproof compound.

"We have discovered that by coating or covering the surface of wires andconductors for electrical purposes with a mixture of bisulphide ofcarbon and maltha, as hereinafter specified, a protecting surface orcovering will be producedand obtained that is both an ex cellentprotecting medium against the action of water and moisture and theinfluences of the weather and an cfficient insulator of the wire orconductor from other surrounding conducting surl'aces or objects. itselfis new, and it may be made with many variations of its incidentalqualities, such as are common to other substances, and yet all. of thenewly-found characteristics which are peculiar to itself will bepreserved. Upon the compound itself Letters Patent have been granted tous, No. 838,868, dated March 30,

5 1886, and the formula given in said Letters Patent is employed by usin this invention when found applicable.

The following is a description of the mode in which our compound shouldbe prepared 0 for producing and carrying out our said invention but wewould not be understood as limiting ourselves thereto, as theproportions may be varied to make a thicker or a thinner composition.

It is better to make our new compound thicker forsoine purposes-snch,for instance, where the electrical wire or conductor is to be laid orembedded in a trough or trench underground or in wooden or metalconduits-than it should The compound I be when it is intended to beapplied as a coat 5o ing or covering to the wire or conductor eitheralone or in connection with awrapping orcovering of textile or fibrousmaterial around the wire or conductor. On account of this fact we willherein specify enough of the various pro- :5 portions in which thebisulphide of carbon should be mixed with maltha, in order to make thecompound of any desired consistency and quality. to illustrate thenature of the mixture and enable persons skilled in the art of coveringelectric wires and conductors and producing insulated conductors of thekind to make any grade desired of the compound which the bisulphide ofcarbon and maltha is capable of producing when mixed together, both whenother substances are and when they are not mixed in the compound.

e make the compound very limpid by combining forty (40) parts ofbisulphide of carbon and sixty ((30) parts of maltha. \Ve 70. also makethe compound extremely heavvand stiff by mixing twenty-five (25) partsof bisulphide of carbon with twenty-five 25) parts of refined maltha andtwentyiive (25) parts of refined asphalt. This mixture is as thick inconsistency as could well be applied with a brush; but the form ofcomposition which we prefer to use is produced by mixing togethersixty-six (BIS) parts of refined maltha and thirty-four (34) parts ofbisulphide of carbon, as we find those proportions give satisfactoryresults. This form of the mixture is recommended both for coating thewire and for treating the wrapping or fibrous covering. 13y us ing alarger proportion of maltha than any 8 herein mentioned the compound canbe made U so nearly solid that it can be applied with a trowel orsimilar instrument. All the proportions herein given are intended to beas certained by weight. 0

In this compound the various wellknown properties of various substancesare employed to produce their natural eftcets-as for instance, asphalttends to make the com pound more tenacious and adds body to it. 5

Sulphur furnishes hardness and smoothness of surlace, but makes it morebrittle when it Rosin tends to make the corn becomes dry.

pound flow more freely, and also adds hardness to it. Parafiine makes itmore elastic and pliable. Therefore, when desirable to give the compoundspecial characteristics for special purposes, a proportion may be addedto the compound of any of these substances.

In proceeding to carry out our invention we form a covering upon thesurface of the wire by applying the compound in a coat or in successivecoats laid one upon the other directly to the wire and either byspreading it upon the wire by means of brushes or suitable implements insuch manner as to produce an even coating of uniform thickness, or, aswill be found the more practicable in treating a considerable length ofwire, by running the wire through the compound. In this opera tion theapparatus can be of the character used for coating wire with othersubstances and materials; but where the wire is to be used in situationsexposed to rubbing contact with surfaces and objects, and be subject toabrasion, and where a covering for cables and sub merged wires isrequired, we employ fibrous or textile material or a braidedcovering,whieh we thoroughly saturate and coat with the compound. Insuch cases we apply a layer or coating of the compound to the surface ofthe wire, and then wrap the woven or fibrous ma terial around the wire,either saturating it at the time of wrapping or immersing the wire inthe compound after being wrapped with the covering. In applying thebraided covering we follow the same course, either saturating the cordor yarn at the time of braiding or immersing the covered wire inthelcompound until thoroughly soaked. In laying electric wiresunderground or in troughs, trenches, or conduits, or in other ways wherethey are designed to lie permanently, we apply the compoundof a thickercharacter or consistency, so.

that the wire is embedded in and covered by the compound. That form ofthe compound before described-as of a thicker or stiff consistency wouldbe serviceable, it being understood that such form of the compound isproduced by changing the proportion of the maltha in the mixture.

In proceeding to produce any of the forms of our said compound we firsteliminate any dirt and objectionable matter in the maltha, and in doingthis we take care to avoid forming any particles of coke or solid matterinto carbon particles by refining the maltha at low temperature. Thecoveringthus applied and produced will be found to be both an effectiveinsulator and a complete protective against the elements. It will befound, also, to resist the action of acids and alkalies, exceptingconcentrated sulphuric acid.

The compound can be applied at normal temperature, and when applied willform a firm tenacious coating and surface. The covering is tough,strong, and pliable, it does not harden or crack, and does not impairthe pliability of the wire. The process of coating the wires is carriedon at normal temperature, neither the wire nor the mixture being heated.The coating is not affected by extremes of heat or cold, nor by moisturein any form, nor by acids, alkali, or saline influences with which itwould come in contact in ordinary conditions of use. It is alsonon-conducting in a very high degree. The good effects named are due tothe character of the mixture which forms the coating.

Having thus fully described our invention, what we claim, and desire tosecure by Letters Patent, is-

1. A wire or conductor for electrical purposes having its surfacecovered or coated by or enveloped in a compound formed by the mixture ofbisulphide of carbon and maltha, substantially as and for the purposesherein set forth.

2. The combination, with a wire or conduct or for electrical purposes,of an insulating protecting covering formed of bisulphide of carbon andmaltha in mixture, and either with or without a wrapping or covering offiber, applied substantially as herein set forth.

TRUMAN J. PEARCE. [L. s.]

MELVIN XV. BEARDSLEY. [L s] Witnesses;

EDWARD E. OSBORN,

L. OSBORN.

